There has conventionally been a light-emitting device using a light-emitting element provided with a light-emitting layer on one main surface of a semiconductor substrate, such as LED (Light Emitting Diode) and LD (Laser Diode). When the light-emitting device is produced, a lead frame having an opening part, with the first lead electrically connected with one electrode of the light-emitting element, and the second lead electrically connected with the other electrode, both projecting to the opening part, is used. In this case, for example, an element mounting part to mount the light-emitting element is provided on the first lead of the lead frame. And one electrode of the light-emitting element and the element mounting part are bonded so as to oppose each other, by conductive adhesive such as a silver-paste, and the other electrode is connected to the second lead by a bonding wire, and the like.
When one electrode of the light-emitting element and the element mounting part (lead) are bonded, as a method for preventing short circuit of an element or light blocking caused by a conductive adhesive flowing outside a bonding area wherein the electrode of the light-emitting element is placed, there is a method, for example, for providing a bonding part of the light-emitting element with a convex chip-mounting part having an upper surface with area equal to or smaller than the bonding area of the light-emitting element, as described in JP-A-5-63242 (hereinafter referred to as Reference 1). In this method, for example, as shown in FIG. 1 of Reference 1, conductive adhesive is dropped on the mounting part, and then a light-emitting diode chip (light-emitting element) is placed on the conductive adhesive dropped, and pressure-bonded. In this pressure-bonding, excess conductive adhesive is extruded from between the light-emitting diode chip and the light-emitting diode chip-mounting part, however, the overflowing conductive adhesive flows into a lower part surrounding the mounting part because the mounting part has convex shape, which enables to prevent a bond from heaping up on the mounting part, or from contacting with the end surface of the light-emitting diode chip.
As a method for preventing short circuit of an element or light blocking caused by a conductive adhesive flowing outside the bonding area, besides the method described in Reference 1, for example, as described in JP-A-2001-352100 (hereinafter referred to as Reference 2), there is a method for providing a bonding part of the light-emitting element with at least two concave grooves at least in the same direction to keep the conductive adhesive in the concave grooves. In this method, for example, as shown in FIGS. 1(a) and 1(b) of Reference 2, a plurality of striped concave grooves are formed on the bottom surface of a cup-shaped concave part formed at the tip of the first lead, and bonding material is retained in the concave grooves. In this state, even if bonding material is sufficiently applied to ensure bonding of the LED chip (light-emitting element), most of the bonding material is received in the concave grooves, and the bonding material remains only slightly on the surface, and practically does not heap up. Therefore, even when an LED chip is provided thereon, the bonding material hardly climbs up extremely on the side surface of the LED chip substrate.